Aromatic amines are commonly used in the preparation of hardeners for thermosetting resins such as polyurethanes and epoxy resins. Aromatic amines are solid at room temperature and generally not available in a liquid form at room temperature, thus making the processing of these materials in the preparation of polyurethanes and epoxy resins difficult. The use of aromatic amines typically requires a melt-into-resin technique, where the resin is preheated and the melted amine added to it. While this technique is industrially acceptable, the industry must contend with poor working lives of the resin-hardener mixture. In addition, such use of aromatic amines has many drawbacks including exposure to amine dust, heating requirements, and air entrapment.
Presently there are no commercially available products which are true solutions of aromatic amines but rather dispersions of finely powdered aromatic amine in very polar solvents or non reactive solvents having plasticizing or other deleterious effects. Dispersion products employing very polar solvents are difficult to handle as they tend to have very high vapour pressures and therefore susceptible to evaporation at ambient temperatures. Dispersion products employing non reactive solvents may adversely affect the properties of the resulting polyurethane or epoxy resins. When these dispersion products are used for the preparation of epoxy resins, the resulting materials are typically brittle and may have other undesirable properties. These dispersion products are also not suitable for the preparation of polyurethanes as they cure too fast with urethanes.